This invention relates to an endoscope tip useful for viewing and inspecting relatively inaccessible objects. More specifically, the invention is particularly useful in an industrial endoscope used to inspect weld joints provided interiorly of piping and in jet engine combustion chambers.
FIG. 1 shows an endoscope 101 having a conventional or prior art tip 105 located internally of a jet engine in position to inspect a weldment 103 provided between a projecting edge 108 of one part and a liner 102. FIG. 2 shows an end view of the prior art tip 105 which is provided with an observing window 106 and three illuminating windows 107.
The center 0.sub.1 of the observing window 106 is separated by a distance L.sub.1 from the periphery of the tip 105. The center 0.sub.1 represents the axis of the objective lens system located in the tip 105 behind the observing window 106 and, as illustrated by FIG. 1, there are instances where the distance L.sub.1 is too great to permit adequate viewing or illumination of an object to be inspected. For example, in FIG. 1 the projecting edge part 108 intercepts the axis 0.sub.1 of the objective lens system thereby disrupting the visual field and preventing an adequate image of the weldment 103 for inspection purposes. The amount of light available to illuminate the weldment 103 may also be localized or totally inadequate since the illuminating windows 107 are rotated out of the limited field of vision as the observing window 106 is positioned closely adjacent the inner surface 102a of the liner 102.